JPS58149935A - Modified polyolefin composition - Google Patents

Abstract

PURPOSE:To provide a modified polyolefin compsn. which has excellent adhesiveness and gives moldings having excellent impact resistance particularly at low temperature, by reacting an olefin rubber with a reaction product between crystalline polypropylene and maleic acid in the presence of a radical initiator. CONSTITUTION:0.01-2pts.wt., pref. 0.01-0.4pts.wt. maleic acid is melt-reacted with 100pts.wt. crystalline ethylene/propylene random copolymer having a melt flow index of pref. 0.2-5 in the presence of 0.01-2pts.wt., pref. 0.01-0.2pts.wt. radial initiator such as tert-butyl peroxybenzoate. An olefin rubber such as ethylene/propyelene copolymer rubber is melt-mixed with the above reaction product in such a proportion that the resulting compsn. has an olefin rubber content of 5-30wt%, to obtain a modified polyolefin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified polyolefin composition which has excellent adhesion and also provides molded articles with excellent impact resistance, particularly impact resistance at low temperatures.

In this specification, the low-temperature impact resistance of the modified polyolefin composition is determined by molding the modified polyolefin composition into a press sheet in accordance with ASTM D746, and using the press sheet as a dumbbell-shaped (38 mm) test piece for measuring the embrittlement temperature. , x 6 x 2 m+) to make a test piece, and the judgment was made based on the embrittlement temperature measured using this test piece. This embrittlement temperature is 1 for each temperature.
Using 0 test pieces, impact is applied to each test piece to determine the fracture rate (percentage of fractures among 10 test pieces), and the fracture rate is determined by plotting the measurement temperature and fracture rate. is 5
It refers to the temperature of 0 degrees. The lower the embrittlement temperature, the better the impact resistance of the modified polyolefin composition, especially the impact resistance at low temperatures.

Crystalline polypropylene is used in a wide range of applications, such as injection molded products, films, and blow bottles, in various fields where physical properties such as rigidity and heat deformation resistance are required. However, since crystalline polypropylene does not have a polar group in its molecule, it has the disadvantage of extremely poor adhesion to different materials such as synthetic resins, metals, and wood.

Various attempts have been made to provide adhesive properties to crystalline polypropylene.

For example, there are surface treatments such as flame treatment, corona discharge treatment, and solvent treatment on the adhesive surface of crystalline polypropylene, but even these methods cannot impart sufficient adhesiveness to crystalline polypropylene.

Therefore, attempts have been made to impart adhesive properties to crystalline polypropylene by adding maleic acids to crystalline polypropylene in the presence of a radical initiator and introducing functional groups, but this method is not sufficient. However, it has low impact resistance at low temperatures and is not practical.

The present inventors completed this invention as a result of extensive research aimed at obtaining a modified polyolefin composition that has strong adhesive strength and excellent impact resistance at low temperatures.

That is, the present invention is characterized in that it is obtained by melting and reflecting a crystalline ethylene-propylene random copolymer, maleic acids, and a radical initiator, adding an olefin rubber to the obtained reaction product, and melt-mixing. This invention relates to a modified polyolefin composition.

In the present invention, as crystalline polypropylene.

A crystalline ethylene-propylene random copolymer is used. The crystalline ethylene-propylene random copolymer has an ethylene content of 0.5 to 5% by weight and a melt flow index of 0.1 to 20. Especially from the point of view of impact resistance.
2 to 5 are preferred. A portion of the crystalline ethylene-propylene random copolymer may be replaced with a crystalline propylene homopolymer. In addition, in the crystalline ethylene-propylene random copolymer, various additives (1) may be added as long as they do not decompose with a radical initiator when heated to a temperature higher than the melting temperature and do not cause color development (1) or yellow odor (1). An antioxidant may be added. Further, the crystalline ethylene-propylene random copolymer may be in the form of powder or pellets.

Next, the term maleic acids used in this invention includes maleic acid, fumaric acid, mezaconic acid, latranic acid, 5-norbornene-2,3-dicarboxylic acid, 1
, 2,3.6-titrahydrophthalic acid.

It is a general term for these anhydrides, these amides, and these monoesters. Among these, maleic anhydride is preferred.

Next, as the radical initiator used in this invention, an azobis compound such as azobisisobutyronitrile, and an organic peroxide 2 having a 1-minute half-life temperature of about 160 to 260°C. For example, tert-butyl peroxyisopropyl carbonate, di-tert-butyl peroxyisopropyl carbonate.

tertiary-butylperoxyacetate), 2,5-dimethyl-2,5-cy(benzoylperoxy)hexane, tertiary-butylperoxylaurate.

Tert-butyl peroxybenshade, methyl ethyl ketone peroxide, dicumyl peroxide, cyclohexanone peroxide, tert-butyl cumyl peroxide, diisobrobyl benzedihydroperoxide.

Examples include cumene hydroperoxide.

These organic peroxides can be used alone or in combination of two or more.

What is the blending ratio of the crystalline ethylene-propylene random copolymer, maleic acids, and radical initiator?

0.01 to 2 parts by weight of maleic acids 1% to 100 parts by weight of crystalline ethylene-propylene random copolymer
is 0.01 to 0.4 parts by weight, and the radical initiator is 0.
．． It is preferably 0.01 to 2 parts by weight, particularly 0.01 to 0.2 parts by weight. Still, it is preferable that the ratio of maleic acids (MA) to the radical initiator (R) (FtI/MA, weight ratio) is 0.1 to 5.

In this invention, it is first necessary to melt-react a crystalline ethylene-propylene random copolymer, maleic acids, and a radical initiator in the substantial absence of an olefin rubber. When a crystalline ethylene-propylene random copolymer, a maleic acid, a radical initiator, and a gold olefin rubber are subjected to a melt reaction together, the adhesive strength of the modified polyolefin decreases, and the impact resistance at low temperatures significantly decreases ( Comparative example 1).

The modified polyolefin composition of the present invention is produced by subjecting a crystalline ethylene-propylene random copolymer, maleic acids, and a radical initiator to a melt reaction in the substantial absence of an olefinic rubber as described above, and adding the resulting reaction product to the resulting reaction product. Obtained by adding olefin rubber and melt-mixing.

Olefinic rubber used in this invention ′-(
(Also referred to as elastomer) include ethylene-lene-nonconjugated diene 6-component copolymer lac, ethylene-propylene-butene-13 component copolymer rubber! Examples include polyimbutylene and 1,2-polybutadiene. Among them, ethylene-propylene copolymer rubber and ethylene-propylene-nonconjugated diene six-component copolymer LANOKU are particularly preferred. Part of the olefin rubber is styrene-butadiene copolymer rubber, butadiene-styrene-acrylonitrile copolymer lac, cis-1,4
- polybutadiene, chloroprene run<-, natural rubber,
Of course, those substituted with rubber such as urethane rubber or ethylene-vinyl acetate copolymer rubber can also be used as the olefin rubber.

Olefin rubbers can be used alone or in combination of two or more. Also, in olefin rubber, when heated to a temperature higher than the melting temperature, it decomposes and develops one color.
Various rubber compounding agents 1 such as anti-aging agents such as antioxidants and anti-adhesive agents such as fatty acid metal salts may be blended as long as they do not cause odor. Also,
Olefin rubber is Mooney viscosity MLI. 4(ioo
C) is preferably 10 to 100.

The modified polyolefin/composition of the present invention is produced by subjecting a crystalline ethylene-propylene binary copolymer, maleic acids, and a radical initiator to a melt reaction as described above, adding an olefin rubber to the resulting reaction product, and melting it. Although it is obtained by mixing, the apparatus used for the above-mentioned melt reaction or melt mixing may be a general mixing machine such as a Banbury mixer, a kneader, a mixing roll, or an extruder.

The melting reaction can be easily carried out by using these mixers alone or in combination, but the above melting reaction may also be carried out in the presence of a solvent. Also, prior to the melt reaction and melt mixing described above, two usually crystalline ethylene-propylene lantum copolymers, maleic acids, and a radical initiator are triblended.

In addition, the temperature for melt reaction or melt mixing is appropriately selected in consideration of the crystalline ethylene-propylene random copolymer, deterioration of the olefin rubber, decomposition temperature of the Rancal initiator, etc.; It is above the melting point of the propylene random copolymer, and is usually 170 to 27.
The temperature is within the range of 0°C.

The modified polyolefin composition of the present invention can be produced by adding and melt-mixing an olefin rubber to a reaction product resulting from a melt reaction of a crystalline ethylene-propylene random copolymer, maleic acids, and a radical initiator. A significant effect is achieved in that the impact resistance, especially at low temperatures, is increased.

In the present invention, the above-mentioned olefin rubber is.

The proportion of the olefin rubber in the total amount of the reactant and the olefin rubber is 1 to 40% by weight, especially 5 to 30% by weight.
It is preferable to use an amount that satisfies the following. If the blending ratio of the olefin rubber is outside the above range, the adhesion, impact resistance, and moldability (film formation) will deteriorate.

powder, etc.), heat resistance, etc., tends to be difficult to obtain.

Furthermore, the modified polyolefin composition of the present invention can be prepared by the method described above, particularly preferably by adding 0.01 to 0.4 parts by weight of maleic acids and 0.01 parts by weight based on 100 parts by weight of the crystalline ethylene-propylene random copolymer. The following effects can be achieved by adding and melt-mixing an olefin rubber to a reactant that has been melt-reacted with ~0.2 parts by weight of a radical initiator.

(1) Since the modified polyolefin composition of the present invention can suppress the amount of maleic acids used, the complicated process 1 for removing unreacted maleic acids after modification is required. It is possible to omit the post-treatment of treating the modified polyolefin composition with warm or hot air for 6 to 8 hours, or with warm or hot water for 1 to 5 hours, as described in the above publication. Become.

(2) It is now possible to produce a modified polyolefin composition that is substantially free of gel, and the melt flow index does not change even if this modified polyolefin composition is exposed to high temperatures for a long time, improving moldability and product appearance. Favorable properties are retained.

The modified polyolefin composition of the present invention includes antioxidants, weathering stabilizers, lubricants, antistatic agents, nucleating agents, fillers, pigments, dyes, flame retardants, and antiblocking agents in the types and amounts normally incorporated into crystalline polypropylene. .

A slimming agent or the like may also be included.

The modified polyolefin composition of the present invention is an unmodified crystalline polypropylene, such as a crystalline homopolymer of propylene,
It can be used in combination with a crystalline ethylene-propylene random copolymer, a crystalline ethylene-propylene block copolymer, and the like.

In this case, from the viewpoint of adhesive properties, the proportion of unmodified crystalline polypropylene is preferably 900 parts by weight or less, particularly 500 parts by weight or less, based on 100 parts by weight of the modified polyolefin composition.

In addition, when a resin molded article with particularly excellent mechanical strength such as tensile strength is required, inorganic fillers 1 such as calcium carbonate, Merck, and clay can be used.

Alumina, zinc white, magnesium oxide, diatomaceous earth.

Mica, calcium sulfite, calcium sulfate, carnoum silicate, glass powder, glass fiber, asbestos.

Gypsum fiber, kaolin, calcined kaolin, carbon fiber.

A desired product can be easily obtained by blending an appropriate amount of fibrous magnesium oxysulfate or a mixture thereof or aromatic polyamide fiber. The shape or size of the above-mentioned inorganic filler is not particularly limited, but when it is in the form of two particles, it is preferable that the average particle size is 10 μm or less.

It is blended in an amount of 450 parts by weight or less, preferably 10 to 300 parts by weight, based on 100 parts by weight of the above-mentioned modified polyolefin composition, from the viewpoint of the balance of mechanical properties and moldability.

The modified polyolefin composition of the present invention having the above composition has a embrittlement temperature of 120°C or less, has superior adhesiveness and impact resistance of molded products compared to conventional polypropylene, and has sufficient heat resistance. sex.

It has moldability and can be used for metals, various plastics,
It can be bonded to various other materials easily and with sufficient strength, and the molded article thus obtained has excellent impact resistance due to the modified polyolefin composition.

Next, Examples and Comparative Examples will be shown.

In Examples and Comparative Examples, crystalline polypropylene,
The melt flow index of the modified polyolefin composition was measured according to ASTM D1238, and the Mooney viscosity of the olefin rubber was ML1+4.
(100°C) was measured according to J-Ko SK6RO00.

In the following description, parts mean parts by weight.

Examples 1 to 4 Ethylene content 6% by weight, Melt Flow Intex (M
, T) Maleic anhydride and tert-butyl peroxybenzoate were added in the amounts shown in Table 1 to a pellet of 100 parts of a 1.0 crystalline ethylene-propylene random copolymer (containing 11,000 ppp of BHT), and After thorough mixing in a shell mixer, a melt reaction was carried out in a single-screw extruder at a temperature set at 190° C. at the forefront of the cylinder to obtain pellets of modified polypropylene as reactant 9. Next, Mooney viscosity MLI+4 (100 parts) was added to 80 parts of this pellet.
℃) approx. 70. 20 parts of ethylene-propylene copolymer rubber with an ethylene content of approximately 80% by weight (11000p BIT)
P + (containing 8000 ppm of calcium stearate) pellets were added and thoroughly mixed in a cone blender, then melt-mixed in a single-screw extruder at a set temperature of 190° C. at the forefront of the cylinder, and pelletized.

Using the obtained pellets of the modified polyolefin composition, a sheet was press-molded and punched into dumbbells to create a test piece for measuring the embrittlement temperature.

Peel strength (indicating adhesiveness) measurement sheets were prepared by the following method and each sheet was subjected to a test.

These results are shown in Table 1.

Preparation of sheet for peel strength measurement Grid blasted steel plate (88'-41°200
After heating t) to 200°C, pellets of the modified polyolefin composition If210°C x 100K
Paste a sheet of a modified polyolefin composition (200 x 200 fcn x O, 3ttnt) formed into a sheet under the conditions of g / - x 1 minute (preheating 210 ° C. x 6 minutes),
Allow to melt thoroughly (2 minutes). Next, add a layer of 2cm thick on top of this.
Place a sheet of crystalline polypropylene, q, 1/
After applying a load of - and keeping it heated for a minute, it was cooled to room temperature while the load was being applied to obtain a sheet for peel strength measurement.

Peel strength measurement Using a tensile tester to measure the peel strength of the sheet.

The peel strength was measured by peeling at 90 degrees at a tensile rate of 10 wn/min.

Comparative Example 1 Crystalline ethylene-propylene random copolymer and maleic anhydride with exactly the same El incorporation ratio as Example 2.

After thoroughly mixing tert-butyl peroxy/benzoate and ethylene-propylene copolymer rubber in a Hennel mixer, a melt reaction is performed in a single-screw extruder at a temperature of 190°C at the forefront of the cylinder to form pellets of the modified polyolefin composition. Obtained. The results are shown in Table 1.

Comparative Example 2 The same procedure as Example 2 was carried out except that tert-butyl peroxybendoate was not blended. The results are shown in Table 1.

Example 5 Pellets obtained by melt-mixing modified polypropylene pellets and ethylene-propylene copolymer rubber pellets, and then pelletizing the mixture.

The same procedure as in Example 2 was carried out except that vacuum drying was carried out at 100° C. for 1 day. The results are shown in Table 1.

Example 6 The same procedure as in Example 2 was carried out except that 70 parts of modified polypropylene pellets and 30 parts of ethylene-propylene copolymer rubber pellets were melt-mixed.

The results are shown in Table 1.

Example 7 The amount of tert-butyl peroxybenzoate was 0.05
The same procedure as in Example 5 was carried out except that the amount was changed from 1 part to 0.03 part. The results are shown in Table 1.

The results shown in Table 1 show that the modified polyolefin composition of the present invention has excellent adhesive properties and low-temperature impact resistance, and can be used practically.

Patent applicant: Ube Industries Co., Ltd.

Claims (3)

[Claims] (1) Crystalline ethylene-propylene random copolymer,
A modified polyolefin composition characterized in that it is obtained by melt-reacting maleic acids and a radical initiator, adding an olefin rubber to the resulting reaction product, and melt-mixing the mixture. (2) 100 parts by weight of crystalline ethylene-propylene random copolymer is mixed with 0.01 to 2 parts by weight of maleic acids and 0.01 to 2 parts by weight of a radical initiator, and 1 reactant and olefin-based The modified polyolefin according to claim 1, which is obtained by adding to the reactant an amount of olefin rubber such that the ratio of the olefin rubber in the total amount with the rubber is 1 to 40% by weight. Composition. (3) Crystalline ethylene-propylene random copolymer 1
0.00 parts by weight. ．． 01 to 0.4 parts by weight of maleic acids and 0.01 to 0.2 parts by weight of a radical initiator are blended, and the proportion of olefin rubber in the total amount of the two reactants and olefin rubber is 5 to 30 parts by weight. % of the olefin rubber is added to the reactant.